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