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