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