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