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