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