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