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