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