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