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