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