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