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