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