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