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