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