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