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