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