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