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