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)(26,31)(27,33)(28,35)(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)(25,26,30,31)(27,29,33,39)(28,36,35,32)(34,40,37,38)(2,7)(3,8)(11,19)(13,16)(20,24)(21,22)(25,27,30,33)(26,29,31,39)(28,37,35,34)(32,40,36,38)(1,4,5,6)(2,3,7,8)(9,12)(10,14)(11,20)(13,22)(15,17)(16,21)(18,23)(19,24)(25,26)(27,29)(28,32)(30,31)(33,39)(34,38)(35,36)(37,40)(1,2)(3,4)(5,7)(6,8)(9,13)(10,11)(12,22)(14,20)(15,16)(17,21)(18,19)(23,24)(25,28,30,35)(26,32,31,36)(27,34,33,37)(29,38,39,40)(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)(26,33)(27,31)(28,38)(30,39)(32,37)(34,36)(35,40) 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.