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