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