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