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