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)(11,14)(12,20)(13,17)(15,19)(16,22)(18,24)(21,23)(25,26)(27,34)(28,29)(30,31)(32,37)(33,38)(35,40)(36,39)(1,3,6,5)(2,7,4,8)(9,11,13,19)(10,14,17,15)(12,21,22,18)(16,24,20,23)(26,31)(28,33)(32,34)(35,39)(1,3,6,5)(2,8,4,7)(9,11)(10,15)(12,18)(13,19)(14,17)(16,24)(20,23)(21,22)(25,26,30,31)(27,32,37,34)(28,29,33,38)(35,36,39,40)(9,10)(11,14)(12,16)(13,17)(15,19)(18,23)(20,22)(21,24)(25,27,30,37)(26,32,31,34)(28,35,33,39)(29,36,38,40)(1,4,6,2)(3,7,5,8)(9,11)(10,15)(12,18)(13,19)(14,17)(16,24)(20,23)(21,22)(25,28,30,33)(26,29,31,38)(27,35,37,39)(32,36,34,40)(1,5,6,3)(2,7,4,8)(9,12)(10,16)(11,18)(13,22)(14,23)(15,24)(17,20)(19,21)(25,29)(26,33)(27,36)(28,31)(30,38)(32,39)(34,35)(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.