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