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