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)(11,13)(12,17)(14,16)(15,18)(19,22)(20,21)(23,24)(25,26)(27,32)(28,38)(29,33)(30,39)(31,34)(35,36)(37,40)(2,5)(3,8)(9,11,14,18)(10,15,16,13)(12,19,20,24)(17,23,21,22)(25,27,31,37)(26,32,34,40)(28,33,39,35)(29,30,36,38)(1,3)(2,6)(4,5)(7,8)(10,16)(12,20)(13,15)(19,24)(25,28,31,39)(26,30,34,38)(27,35,37,33)(29,40,36,32)(1,4,7,6)(2,3,5,8)(9,12,14,20)(10,17,16,21)(11,19,18,24)(13,22,15,23)(25,28)(26,30)(27,33)(29,40)(31,39)(32,36)(34,38)(35,37)(1,5,7,2)(3,4,8,6)(9,10)(11,15)(12,21)(13,18)(14,16)(17,20)(19,22)(23,24)(25,29,31,36)(26,33,34,35)(27,30,37,38)(28,32,39,40)(1,6,7,4)(2,8,5,3)(9,13,14,15)(10,18,16,11)(12,22,20,23)(17,24,21,19)(25,30)(26,28)(27,36)(29,37)(31,38)(32,33)(34,39)(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.