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)(21,22,26,30)(23,28,32,36)(24,29,25,27)(31,35,33,34)(5,7,9,15)(6,10,12,19)(8,17,18,14)(11,20,16,13)(22,27)(24,25)(28,35)(29,30)(31,33)(34,36)(2,4)(21,23)(22,28)(24,31)(25,33)(26,32)(27,34)(29,35)(30,36) involution — undirected(21,24,26,25)(22,29,30,27)(23,31,32,33)(28,35,36,34)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.