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