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