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