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