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