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