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