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