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