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