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