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