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