Space travel times are often adjusted for the sake of plot, but if you're someone like me and prefers to meticulously work out the realistic time it takes for space travel in a universe and work your story and characters around it, then here is a guide for doing so for the Mass Effect: Cybele forum roleplay!
In Mass Effect, travel from one mass relay to another is near-instantaneous; thus, using the relay network itself would take very little time. Most of the time navigating the relays will likely be spent on procedure, things like calculations and waiting to be cleared for launch (imagine waiting for an airport runway). The intro of the first Mass Effect game has an excellent demonstration of what that is like.
However, just because travel in the relay network is very quick doesn't mean space travel time is negligible. Mass relays are not always located near your destination, they can sometimes be in an adjacent solar system, or on the other side of a cluster. Under these circumstances, the ship must use conventional FTL to traverse the remaining distance.
On average, ships in Mass Effect travel around a dozen light years per day. One light year is 9.461x1012 km (roughly one trillion kilometers). This means that in an hour, a ship with a mass effect drive can cover a distance of one-half light year, or 4.7305x1012 km (7.884x1010 km/min).
The entire width of the Sol system (counting from Sedna, the furthest known object in our solar system) is 2.87x1011 km (287.46 billion km), which means that a ship can traverse one end of the system to the other within just 3.6 minutes. Travel times from planet to planet in a system is drastically less than that, being within the fraction of a minute. Thus, inter-system travel time in Mass Effect is entirely negligible.
Travel times from one system to another, however, is a different story. Alpha Centauri, the closest solar system to ours, is 4.3 light years away, meaning that it would take over eight hours for a ship to travel there. Most forms of star clusters range from being ten to thirty light years in diameter, meaning that crossing from one end of a cluster to the other would take anywhere between the better part of a day to two and a half days.
So, how long would it take to travel to Cybele?
Cybele is located in the Enyalius system, just outside the Hades Gamma Cluster, which, judging from the other cluster images from the Mass Effect games, appears to be a medium-large cluster. As such, its diameter is likely to be within the 20-25 light years range. We will work with 22 light years. The mass relay connection in Hades Gamma is in the Antaeus System, which is roughly halfway in between two ends of the cluster. To reach Cybele, a ship must first pass one of these ends, meaning that they would travel 22 hours to do so. The Enyalius system is just outside, but considering that stars are less concentrated outside a cluster, it is probably at least 4 light years away from the cluster's edge. By these numbers, it would take over 30 hours for a ship to travel from the Antaeus relay to Cybele.
Adding in calculations for mass relay jumps, formal procedures related to relays and undocking or potentially even refueling time, it would probably take a ship between 31 to 33 hours to travel from a system with a mass relay to Cybele, depending on the area of departure (strictness of docking regulations, relay activity and number of relay jumps required). If departing from a system without a relay, travel time to the nearest relay will increase this number significantly.