One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6,9,12)(7,13,15,20)(8,16,18,11)(10,17,19,14)(21,22,26,25)(23,27,31,30)(24,28,33,32)(29,35,36,34)(5,7,9,15)(6,10,12,19)(8,17,18,14)(11,20,16,13)(21,23)(22,27)(24,29)(25,30)(26,31)(28,34)(32,35)(33,36)(21,24)(22,28)(23,29)(25,32)(26,33)(27,34)(30,35)(31,36) involution — undirected(2,4)(21,25,26,22)(23,30,31,27)(24,32,33,28)(29,35,36,34)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.