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