La Loma, a classic cycling spot where the climb from San Gregorio ends (if you're coming from Xochimilco), is also the crowning glory when coming from Tlayacapan (30 km, almost all uphill, 1,200 m total climb) or Juchitepec (8 km, 350 m total climb).
You can enjoy the panoramic view with quesadillas, coffee, beer, pulque, etc. Weather permitting, you'll be able to see the volcanoes in the distance. Whether you're heading elsewhere, a stop here is definitely a must.
Enjoy the view and have a safe trip to your destination!