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