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