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