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