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