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)(15,18)(19,22)(20,21)(23,24)(25,26,31,29)(27,35,30,32)(28,34,38,33)(36,39,37,40)(3,7)(6,8)(9,11)(10,14)(12,19)(13,18)(15,17)(16,22)(20,23)(21,24)(25,27,31,30)(26,32,29,35)(28,36,38,37)(33,39,34,40)(1,2)(3,6)(4,5)(7,8)(11,18)(14,15)(19,24)(22,23)(25,28,31,38)(26,33,29,34)(27,36,30,37)(32,39,35,40)(9,11)(10,15)(12,19)(13,18)(14,17)(16,23)(20,22)(21,24)(25,28)(26,34)(27,36)(29,33)(30,37)(31,38)(32,40)(35,39) involution — undirected(1,3)(2,6)(4,7)(5,8)(9,10)(11,14)(12,20)(13,17)(15,18)(16,21)(19,23)(22,24)(25,29,31,26)(27,32,30,35)(28,34,38,33)(36,39,37,40)(1,2)(3,6)(4,5)(7,8)(9,12)(10,16)(11,19)(13,21)(14,22)(15,23)(17,20)(18,24)(25,30,31,27)(26,35,29,32)(28,37,38,36)(33,40,34,39)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.