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