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