there is lots of one day trips to take with the travel tour guides that will flag you down
If you're the adventurous type i'll say Xplor or Xplor Fuego... If you book in advance from their site you get a bigger discount. Also check out the mayan ruins in tulum. I'd rent a car at the airport as it costs more to do so at the resort/hotel. Transportation is very expensive some site adventure tours offer free transport so you can look them up.
If you are going as a group and want to have a fun day in a pretty palce, then take a boat trip to Isla Mujeres It's a nice little island, not far from Cancun with nice beaches and a laid back vibe.