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)(11,18)(12,15)(13,20)(14,16)(17,22)(19,23)(21,24)(25,26,31,30)(27,32,37,35)(28,33,38,40)(29,39,36,34)(1,3)(2,5)(4,8)(6,7)(9,11,15,14)(10,16,12,18)(13,19,22,21)(17,23,20,24)(25,26,31,30)(27,35,37,32)(28,33,38,40)(29,34,36,39)(9,10,15,12)(11,18,14,16)(13,17,22,20)(19,24,21,23)(25,27,31,37)(26,32,30,35)(28,36,38,29)(33,34,40,39)(2,6)(5,7)(9,12,15,10)(11,16,14,18)(13,20,22,17)(19,23,21,24)(25,28)(26,33)(27,36)(29,37)(30,40)(31,38)(32,34)(35,39)(1,3)(2,5)(4,8)(6,7)(9,13)(10,17)(11,19)(12,20)(14,21)(15,22)(16,23)(18,24)(25,29,31,36)(26,34,30,39)(27,28,37,38)(32,40,35,33)(1,2)(3,5)(4,6)(7,8)(9,14,15,11)(10,16,12,18)(13,21,22,19)(17,23,20,24)(25,30,31,26)(27,35,37,32)(28,33,38,40)(29,39,36,34)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.