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