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