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