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