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