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