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