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