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)(14,17)(18,20)(23,29)(27,32)(30,35)(34,36)(1,2)(3,4)(7,11)(10,12)(13,14)(15,18)(16,17)(19,20)(21,22,25,26)(23,27,29,32)(24,28,31,33)(30,34,35,36)(5,6)(7,12)(8,9)(10,11)(13,15,16,19)(14,18,17,20)(21,23,25,29)(22,27,26,32)(24,30,31,35)(28,34,33,36)(5,7,8,11)(6,10,9,12)(21,24)(22,28)(23,30)(25,31)(26,33)(27,34)(29,35)(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.