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