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