Please help me plan a trip to Kerala from Hyderabad

Guys, me & a couple of my friends are planning to visit Kerala this weekend. We'll arrive in Kochi by 3PM on Sunday(22th DEC) and returning from Kochi/Trivandrum via train on the night of Wednesday(25th DEC). So we'll be in Kerala for approximately 3.5days.

Please suggest places to visit, order of visiting them and any other suggestions to make the most out of these 3.5 days in Kerala.