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