One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,8)(4,6)(5,7)(9,10)(11,14)(12,15)(13,16)(17,21)(18,22)(19,23)(20,24)(25,26)(27,35)(28,32)(29,33)(30,40)(31,34)(36,38)(37,39) involution — undirected(9,11)(10,14)(12,19)(13,17)(15,23)(16,21)(18,20)(22,24)(25,27,30,33,31,36,28,37)(26,29,32,35,34,39,40,38)(1,3,5,4)(2,6,7,8)(11,17)(14,21)(18,19)(22,23)(25,28,31,30)(26,32,34,40)(27,33,36,37)(29,38,39,35)(9,12,13,20)(10,15,16,24)(11,18,17,19)(14,22,21,23)(25,29,31,39)(26,33,34,37)(27,32,36,40)(28,38,30,35)(1,4,5,3)(2,6,7,8)(10,16)(14,21)(15,24)(22,23)(26,34)(29,39)(32,40)(35,38)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.