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