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