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