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