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