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