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