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