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