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