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