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