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