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