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