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