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