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