There are relatively limited bus routes island-wide provided by KTEL, and their prices are very reasonable. With thorough planning, you can tour most of the island by bus, check out their website here but be prepared that your schedule will follow their timetables which are not always convenient.  To get the most out of your visit I strongly recommend hiring a car for at least most of your stay, still, you could also explore by bike, land and sea taxi services, and boat tours. Contact me to send you some quotes and options.