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