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