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