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