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