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