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