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