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