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