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