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