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