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)(11,20)(12,18)(13,23)(14,15)(16,19)(17,22)(21,24)(26,29)(27,33)(28,36)(39,40)(1,2)(3,6)(4,7)(5,8)(9,11)(10,17)(12,14)(13,21)(15,23)(16,22)(18,24)(19,20)(25,26,31,29)(27,34,33,30)(28,32,36,38)(35,40,37,39)(1,3,5,4)(2,6,8,7)(9,12,16,13)(10,18,19,23)(11,21,22,14)(15,20,24,17)(25,27,31,33)(26,30,29,34)(28,37,36,35)(32,40,38,39)(9,13,16,12)(10,18,19,23)(11,21,22,14)(15,17,24,20)(25,28,31,36)(26,32,29,38)(27,35,33,37)(30,39,34,40)(1,4,5,3)(2,7,8,6)(9,14,16,21)(10,15,19,24)(11,12,22,13)(17,23,20,18)(25,29,31,26)(27,30,33,34)(28,38,36,32)(35,39,37,40)(9,15)(10,14)(11,18)(12,20)(13,17)(16,24)(19,21)(22,23)(25,30)(26,33)(27,29)(28,39)(31,34)(32,37)(35,38)(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.