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