One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,10)(8,9)(11,12)(13,14,16,18)(15,17,19,20)(21,22,26,31)(23,29,33,36)(24,28,34,35)(25,32,27,30)(6,9)(10,12)(13,15)(14,17)(16,19)(18,20)(21,23,25,24,26,33,27,34)(22,28,30,29,31,35,32,36)(2,4)(15,19)(17,20)(23,33)(24,34)(28,35)(29,36) involution — undirected(5,7,8,11)(6,10,9,12)(21,24,25,33,26,34,27,23)(22,29,30,35,31,36,32,28)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.