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)(6,9)(8,12)(10,11)(13,14)(15,23)(16,21)(17,18)(19,22)(20,26)(24,28)(25,27) involution — undirected(2,4)(13,15,18,26,19,27,16,24)(14,20,21,23,22,28,17,25)(6,10)(9,11)(13,16,19,18)(14,21,22,17)(15,24,27,26)(20,23,28,25)(7,12)(9,11)(13,17,16,22,19,21,18,14)(15,25,24,28,27,23,26,20)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.