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