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