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)(25,26,31,28)(27,32,35,36)(29,33,39,38)(30,37,40,34)(1,2)(3,4)(5,7)(6,8)(9,11,15,14)(10,16,17,20)(12,19,22,23)(13,18,24,21)(25,27)(26,32)(28,36)(29,34)(30,33)(31,35)(37,39)(38,40)(1,3,5,8)(2,6,7,4)(10,17)(12,22)(16,20)(19,23)(26,28)(27,35)(33,38)(34,37)(3,8)(4,6)(9,12,15,22)(10,18,17,21)(11,19,14,23)(13,16,24,20)(25,28,31,26)(27,36,35,32)(29,33,39,38)(30,37,40,34)(1,4)(2,3)(5,6)(7,8)(9,13,15,24)(10,19,17,23)(11,21,14,18)(12,20,22,16)(25,29)(26,33)(27,37)(28,38)(30,36)(31,39)(32,40)(34,35)(1,2)(3,6)(4,8)(5,7)(9,14,15,11)(10,20,17,16)(12,23,22,19)(13,21,24,18)(25,30)(26,34)(27,33)(28,37)(29,32)(31,40)(35,38)(36,39)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.