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