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)(15,25)(16,27)(17,22)(18,23)(19,28)(20,24)(21,26) involution — undirected(1,2)(3,4)(13,15)(14,21)(16,19)(17,20)(18,26)(22,23)(24,27)(25,28) involution — undirected(2,4)(6,9)(10,12)(13,16,20,26)(14,21,24,27)(15,18,17,19)(22,23,25,28)(2,4)(13,17,20,15)(14,22,24,25)(16,18,26,19)(21,28,27,23)(5,7,8,11)(6,10,9,12)(13,18,20,19)(14,23,24,28)(15,26,17,16)(21,22,27,25)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.