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