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