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