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