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