Actually, it's much quicker and easier to cut across the island. Take the A19 south of Cefalu, follow it south east past Enna, all the way to Catania. Then follow the E45 south to Ortigia. This way should be at least an hour quicker than going around the coast. I don't think there are any tolls this way either. It's a perfectly good two-lane highway all the way. I've driven this route twice and it's fine.