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