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