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)(23,27)(24,29)(25,28)(26,31)(30,33)(32,35)(34,36) involution — undirected(1,2)(3,4)(5,7,9,15)(6,10,11,13)(8,16,17,14)(12,20,19,18)(21,23,26,32)(22,27,31,35)(24,25,34,33)(28,36,30,29)(2,4)(22,28)(23,32)(25,33)(27,29)(30,31)(35,36) involution — undirected(6,11)(10,13)(12,19)(18,20)(21,24,26,34)(22,29,31,36)(23,33,32,25)(27,30,35,28)(2,4)(5,8,9,17)(6,12,11,19)(7,14,15,16)(10,18,13,20)(23,32)(24,34)(27,35)(29,36)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.