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