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