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