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