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