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