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