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