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