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)(13,14,18,23,19,21,17,22)(15,24,25,27,26,28,16,20)(5,6)(7,11)(8,10)(9,12)(13,15,19,26)(14,20,21,27)(16,17,25,18)(22,24,23,28)(1,2,3,4)(5,7)(6,9)(8,12)(10,11)(14,21)(20,27)(22,23)(24,28)(7,12)(9,11)(13,16,18,15,19,25,17,26)(14,20,23,24,21,27,22,28)(6,10)(9,11)(13,17,19,18)(14,22,21,23)(15,25,26,16)(20,24,27,28)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.