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