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