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