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