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