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