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