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