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