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