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