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