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