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