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