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