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