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)(15,22)(16,19)(17,20)(18,21)(23,28)(24,26)(25,27)(2,4)(15,23)(16,24)(18,25)(19,26)(21,27)(22,28) involution — undirected(6,9)(10,12)(13,15,17,16)(14,19,20,22)(18,24,25,23)(21,28,27,26)(13,16,17,15)(14,19,20,22)(18,23,25,24)(21,28,27,26)(5,7,8,11)(6,10,9,12)(14,20)(19,22)(21,27)(26,28)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.