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