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