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