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