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