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