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