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