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