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