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