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