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