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