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