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)(21,26,25,27)(5,6,8,9)(7,10,11,12)(13,15,19,26,20,16,18,27)(14,21,22,28,17,25,23,24)(2,4)(6,9)(7,11)(13,16,18,26,20,15,19,27)(14,21,23,24,17,25,22,28)(5,7)(6,10)(8,11)(9,12)(13,17,20,14)(15,25,16,21)(18,22,19,23)(24,27,28,26)(6,9)(7,11)(13,18,20,19)(14,22,17,23)(15,26,16,27)(21,24,25,28)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.