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