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