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