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