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