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