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