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