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