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