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