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