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