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