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