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