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