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