One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,8)(9,11)(10,12)(13,14,17,18)(15,19,20,16)(22,25)(23,27)(5,7,9,12)(6,10,11,8)(13,15,17,20)(14,16,18,19)(23,27)(26,28)(6,11)(8,10)(14,18)(15,20)(21,22,24,25)(23,26,27,28)(1,2)(3,4)(5,7)(6,8)(9,12)(10,11)(13,16)(14,15)(17,19)(18,20) involution — undirected(5,8)(6,12)(7,11)(9,10)(13,14)(15,19)(16,20)(17,18)(21,23)(22,26)(24,27)(25,28) involution — undirectedA 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.