Sure, but it is a little big to hide under a haystack.
You *could* rig camoflage around it, but the city is well defended. Unless the Empire puts serious effort into retaking Fest, or at least conducting a strike against you, your ship should be safe.
The Gallofree Yards GR-75 transport is used by the alliance, but also a popular commercial transport. There is nothing about the ship that overtly indicates it is a rebel ship.
You ship is also small enough that you should be able to slip away undetected when the time comes. It is only 90m in length.