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