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