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