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