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