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