If you are thinking about taking the ADO bus from the Cancun Airport to Playa Del Carmen but no sure how, here if your simple guide. Most international flights arrive at Terminal 3 or the new Terminal 4 in Cancun Airport (see map below). So most of this guide will be for arrivals here.
On our recent map updating trip we stopped by Cancun's new terminal to check it out for you, obviously since we weren't flying out of terminal 4, we could only get into the departure area, not the gates or arrivals.
If you are thinking about taking the ADO bus to Cancun Airport from Playa Del Carmen but no sure how, here if your simple guide (and how to get from the airport as well). Note: Many "official" looking people will offer help when you exit the terminal.