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