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)(25,26,32,38)(27,33,29,35)(28,36,30,34)(31,37,40,39)(1,2)(3,6)(4,7)(5,8)(9,11,14,13)(10,15,17,18)(12,19,21,22)(16,23,20,24)(25,27)(26,33)(28,37)(29,32)(30,39)(31,34)(35,38)(36,40)(1,3)(2,5)(4,8)(6,7)(12,21)(16,20)(19,22)(23,24)(25,28,32,30)(26,34,38,36)(27,39,29,37)(31,33,40,35)(3,8)(5,6)(9,12)(10,16)(11,19)(13,22)(14,21)(15,23)(17,20)(18,24)(25,29,32,27)(26,35,38,33)(28,39,30,37)(31,34,40,36)(1,2)(3,5)(4,7)(6,8)(9,13,14,11)(10,15,17,18)(12,22,21,19)(16,23,20,24)(25,30,32,28)(26,36,38,34)(27,39,29,37)(31,33,40,35)(1,3)(2,6)(4,8)(5,7)(9,10)(11,15)(12,20)(13,18)(14,17)(16,21)(19,24)(22,23)(25,31)(26,37)(27,34)(28,33)(29,36)(30,35)(32,40)(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.