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