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