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