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