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