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)(26,32)(27,36)(29,30)(33,38)(34,37)(35,40) involution — undirected(9,11)(10,14)(12,19)(13,17)(15,23)(16,21)(18,20)(22,24)(25,26,30,32,31,35,29,40)(27,37,28,38,36,33,39,34)(1,3,5,4)(2,6,7,8)(11,17)(14,21)(18,19)(22,23)(25,27)(26,33)(28,30)(29,39)(31,36)(32,34)(35,37)(38,40)(9,12,13,20)(10,15,16,24)(11,18,17,19)(14,22,21,23)(25,28)(26,34)(27,29)(30,36)(31,39)(32,37)(33,40)(35,38)(1,4,5,3)(2,6,7,8)(10,16)(14,21)(15,24)(22,23)(25,29,31,30)(26,32,35,40)(27,28,36,39)(33,38,37,34)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.