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