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