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)(25,26,31,35)(27,32,38,37)(28,39,29,33)(30,34,40,36)(2,7)(3,4)(9,11)(10,16)(12,20)(13,15)(14,21)(17,19)(18,22)(23,24)(25,27,31,38)(26,32,35,37)(28,36,29,34)(30,33,40,39)(1,3,6,4)(2,8,7,5)(11,13)(16,17)(20,22)(21,23)(25,28,31,29)(26,33,35,39)(27,34,38,36)(30,37,40,32)(1,4,6,3)(2,5,7,8)(9,12)(10,14)(11,20)(13,22)(15,18)(16,21)(17,23)(19,24)(25,29,31,28)(26,33,35,39)(27,36,38,34)(30,37,40,32)(1,5)(2,3)(4,7)(6,8)(9,13,15,11)(10,17,19,16)(12,22,18,20)(14,23,24,21)(25,26)(27,37)(28,39)(29,33)(30,34)(31,35)(32,38)(36,40)(9,14)(10,18)(11,21)(12,19)(13,23)(15,24)(16,22)(17,20)(25,30,31,40)(26,34,35,36)(27,33,38,39)(28,37,29,32)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.