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)(13,14,19,22)(15,17,21,23)(16,18,26,28)(20,25,27,24)(6,9)(10,12)(13,15,18,24,19,21,28,25)(14,20,16,17,22,27,26,23)(5,7,8,11)(6,10,9,12)(13,16,18,22,19,26,28,14)(15,23,24,20,21,17,25,27)(2,4)(13,17)(14,21)(15,22)(16,25)(18,27)(19,23)(20,28)(24,26) involution — undirected(15,21)(17,23)(20,27)(24,25) involution — undirectedA 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.