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