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