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