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