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