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