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