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