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