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