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