One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,11)(8,10)(9,12)(13,14,18,19)(15,20,24,28)(16,23,25,21)(17,22,27,26)(5,7)(6,9)(8,12)(10,11)(13,15,18,24)(14,20,19,28)(16,17,25,27)(21,26,23,22)(2,4)(13,16,19,23,18,25,14,21)(15,22,20,17,24,26,28,27)(6,10)(9,11)(13,14,18,19)(15,20,24,28)(16,21,25,23)(17,26,27,22)(7,12)(9,11)(13,17,14,22,18,27,19,26)(15,23,28,16,24,21,20,25)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.