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