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