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