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