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