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