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