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