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