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)(21,22)(23,31)(24,29)(25,28)(26,30)(27,33)(32,35)(34,36) involution — undirected(2,4)(5,7,10,17)(6,11,14,20)(8,16,9,15)(12,19,13,18)(21,23)(22,27)(24,34)(25,33)(26,32)(28,35)(29,31)(30,36)(5,8,10,9)(6,12,14,13)(7,15,17,16)(11,18,20,19)(22,28)(24,25)(27,35)(29,30)(31,36)(33,34)(5,9,10,8)(6,13,14,12)(7,16,17,15)(11,19,20,18)(23,32)(27,36)(31,35)(33,34)(6,14)(11,20)(12,13)(18,19)(23,32)(27,36)(31,35)(33,34) 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.