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