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