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