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)(13,14,18,23)(15,25,17,21)(16,20,24,19)(22,26,28,27)(1,2,4,3)(5,6)(7,10)(8,9)(11,12)(13,15,18,17)(14,21,23,25)(16,28,24,22)(19,27,20,26)(6,9)(10,11)(13,16,19,14,18,24,20,23)(15,21,26,28,17,25,27,22)(5,7,8,12)(6,10,9,11)(13,17,20,26,18,15,19,27)(14,22,16,25,23,28,24,21)(1,3,4,2)(14,23)(16,24)(21,25)(22,28)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.