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