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