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