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