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