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