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