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