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