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