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