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