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