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