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