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