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