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