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