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