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