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