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