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