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