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