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