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