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