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