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