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