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