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