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