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