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