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