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)(25,26,32,30)(27,35,39,33)(28,29,34,31)(36,37,40,38)(1,2,5,4)(3,7,8,6)(9,11)(10,16)(12,20)(13,22)(14,21)(15,19)(17,24)(18,23)(25,27,32,39)(26,33,30,35)(28,40,34,36)(29,37,31,38)(1,3,5,8)(2,6,4,7)(10,12)(11,19)(13,23)(14,24)(25,28)(26,31)(27,36)(29,30)(32,34)(33,37)(35,38)(39,40)(3,8)(6,7)(9,12,15,10)(11,20,19,16)(13,17,23,21)(14,22,24,18)(25,29,32,31)(26,28,30,34)(27,37,39,38)(33,40,35,36)(1,3)(2,7)(4,6)(5,8)(9,13)(10,17)(11,18)(12,21)(14,16)(15,23)(19,22)(20,24)(25,30,32,26)(27,33,39,35)(28,29,34,31)(36,37,40,38)(1,4,5,2)(3,6,8,7)(9,14,15,24)(10,18,12,22)(11,21,19,17)(13,16,23,20)(25,31,32,29)(26,34,30,28)(27,38,39,37)(33,36,35,40)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.