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