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