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