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