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