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)(15,25,16,21)(17,20,23,18)(22,27,28,26)(2,4)(6,10)(11,12)(13,15,19,16)(14,21,24,25)(17,28,23,22)(18,26,20,27)(5,7,9,8)(6,11,10,12)(13,16,18,26,19,15,20,27)(14,22,23,21,24,28,17,25)(1,2,3,4)(13,17,18,14,19,23,20,24)(15,25,27,22,16,21,26,28)(5,8,9,7)(6,11,10,12)(13,18,19,20)(14,23,24,17)(15,26,16,27)(21,22,25,28)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.