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