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