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