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