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