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