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