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