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