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