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