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