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