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