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