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