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