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