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