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