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