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