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