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