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