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