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