Take A19 Palermo-Catania motorway. After about 90 km., take exit  for Caltanissetta and, after few km., take exit for SS. 626 towards Capodarso. Continue until you reach the SS. 115, take the exit. You are now 7 km. from Gela.
Driving time: about 2 hours

There are many signs to Gela. Take the SS. 417, connecting Catania to Caltagirone and continue on SS. 117 bis up to Gela.
Driving time: about 1 hour.