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