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