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