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