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