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