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