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