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