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