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