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