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