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