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