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